Impact drill



INVENTOR. foes/erf. SA/vge,

Arron/vsn 2 SHEETS-SHEET 2 R. E. SNYDER IMPACT DRILL N ly Ei/ZG. 4.

Patented Apr. 21, 1953 IMPACT DRILL Robert E. Snyder, Pasadena, Calif., assignor to Snyder Oil Tool Corporation, a corporation of California Application December 5, 1946, Serial No. 714,339 1s Claims. (o1. c55-a) My invention relates generally to drills used in earth boring, and more particularly to a rotary drill having a hammer which impacts against a constantly rotating bit.

In my previous applications Nos. 527,179, filed March 20, 1944, now Patent No. 2,425,012, issued August 5, 1947, and 674,526, filed June 5, 1946, I have discussed the need for impact drills of this general type and have disclosed several different forms of drills. I have also developed another type of drill which operates in a manner basically similar to that of my previously described drills, but which possesses certain features and advantages not found in any of these prior devices. In the present form I provide an impact-producing hammer which is operated by a fluid motor located on the outside of the drill stem. This motor does not derive its power from the pressure of the mud being pumped through the well, as some other devices have done, but instead is operated by the rotary energy of the drill stem which drives an adjacent pump on that stem.

My present invention is an improvement over the disclosure of my copending ap-plication Serial No. 527,179, filed March 20, 1944, now Patent No. 2,425,012, issued August 5, 1947, and consists essentially of the addition of a helical-blade fluid pump and motor located on the drill stem near the bit to increase the operating frequency of the impact mechanism.

The present invention provides means to increase the magnitude of the resistance acting against the iluid engaging means of the hammer, thereby causing a greater lagging of the hammer with respect to the drill stem and increasing the frequency of impacts delivered to the bit. Broadly, this is accomplished by placing a fluid pump on the drill stem operated by the rotation of the stem to urge a fluid motor mounted on the hammer in the opposite direction.

It is therefore a major object of my invention to provide a rotary drill having a fluid pump and motor assembly at its lower end to reciprocate a hammer which delivers impacts to a bit. It is to be understood that this system is entirely separate and distinct from the pumping system used to circulate the uid or mud customarily used in well drilling. Practically none of the energy of the fluid circulatory system is used in my device, and the latter will, in fact, work equally well when rotated by the drill stem if the mud or fluid inthe V.well merely remains there and is not externally motor which maybe placed in close proximity to each other within a well so that the pump recir- `culates the fluid in the well, outside of the drill stem, to drive the motor.

i It is a further objectof my invention to provide a fluid pump and motor combination wherein the pumped fluid is adapted to retard the rotation of the motor portion with respect to the drill stem.

Still another object of my invention is to pro- .vide a hydraulically-operated rotary impact drill which derives its motive power from the drill stem and which is entirely separate and independent of the fluid circulatory system.

It is still a further object of my invention to provide such a drill in which the discharged fluid may be directedtoward the outer surface of the bit to wash the latter.

These and other objects and advantages of my invention will become apparent from the following description of a simple form and modifications thereof, and from the drawings illustrating those forms in which:

. Fig. 1 is a side elevational view of an impact drill embodying the principles of the present invention with the housing cut away to reveal the interior construction;

v Fig. 2 is a similar View of a modification of the structure shown in Fig. l;

Fig. 3 is a side elevational view of another modification of the drill shown in Fig. l;

A Fig. 4 is a side elevational view of a device similar to that shown in Fig. l, but in which the flow of fluid therethrough has been reversed to secure slightly different results; and

Fig. 5 is a side elevational view of a device having a single motor mounted between two pumps.

i Referring now to the drawings and particularly to Fig. 1 thereof wherein I have illustrated the simplest form of my invention, the numeral I0 indicates a well or hole formed in the earth by my improved impact drill. The drill includes a shank II which is adapted to be attached at its upper end to a conventional drill stem by suitable means (not shown) `and which has an operating head I2 at its lower end provided with means I3 for attaching a standard bit I5 thereto. The attaching means I3 and the means for attaching the shank I I to the drill stem may be of the customary pin and box type threaded coupling commonly used in the art, or any other suitable type. Extending axially through the shank I I is :a bore I6 through which `a uid, commonly termed a fmud, is transferred from the hollow drill stern to the bit I5 where it emerges through an orifice Il intoV the drilled hole I0. In the conventional system, this mud is forced by a pump, located onv up the shaft suspended in the hole to carry the bit. These terms are used in this generally accepted sense throughout this specication and claims.

On the upper end of the operating, head .I2f is` a lower or shank cam which is firmly attached to shank II by welding,A threading, or other suitable means to rotate with the shank at all times, and which provides the impact receiv.

ing face of the drill. Mounted on shank I I above the lower cam 20 is a combinationv hydraulic pump and motor which operates the impact mechanism of the drill. In the form ofdevice shown in Fig. l, a pump 26` is mountedV above a motor 27 and is spaced a slight distance from the latter on shank II. Essentially, pump 26 comprises one or more helical bladesoruid impellers 30 which are attached to shank IIv by welding or othersuitable means tol rotate with the latter at alltimes and drive fluid upwardly. The pitch of the blades 30 is selected' so that with the estimatedl average rotational speedof shank I I, the desired rate of fluid. flow will be secured. As mentioned, this flow is directed upwardly around the outside of. shank II, and a guide tube or housingv 351A completely surrounds the helical blade 30 and extends downwardlyvto a point near the lower. end of. motor 2*'I-.tov substantially enclose the latter. The housing thus confines and directs. the fluidmoved by pump 26 so that it passes through theuid `motor 21, and in this form, the housing is suitably attached to the helical blade 30 4to rotate'with it at all times. Consequently, in the construction of the form shown in Fig. 1, shank II has helical blade 3l) and housing 35 afxed at its upper end, and operating head I2, bit I5, and'lower` cam member 20 atits lower Vend. Since' these members are all firmly and rigidly connected,`they rotate with the shank as a unitary structure.

Motor 2l, which is rotatably and reciprocably mounted on the shank II within theguidetube 35, consists essentially of a central tubular body 4I) having an axial bore 4I.v therein of sumcient size to provide for the free movement of the body` with respect` to the shank. Welded or otherwise suitably attached to the outside of body 40` are one or more helical b1ades42which rotate with the body at allv times, and whoseA pitch is opposite to that of the pump blade 30'. The maximum v diameter of the. helical blade. 42y is such that there isa sufficient clearance between the bladev and the inside of guide tube 35I to avoid all contact between the two,and there is consequently no rubbing ofthe,A blades against the guidetube. It will thusV be seen that the motor 2l consists of the body 4I) with the helical blades 42 rotating withinthe guide, tube 35, and at the lower endof the body, I mount an upper cam 45 Vwhich is shaped Vcomplementally to lower cam 20 and which is driven by themotor toimpact against the lower cam.

When motorY 2Iris rotated-with respect to shank II, upper cam 45 iswrotatedwith respect to lower cam 2u and overrides the latter; to ,raisehe body- 4 40 and then permit it to drop. Sufficient clearance is provided between the upper end of body 40 and the lower end of the helical blade 30 of the pump 26 so that the body may be raised the full distance of the lift of the cams without touching the blade 30. As a result, when the motor 2'1 is rotated it touches only the shank II and the lower cam 20; so that frictional forces are reduced to a minimum. In addition, the overriding of cams 45 and 2l! raises the motor 21 and then allows it to drop to deliver an impactv to the lower cam 2l] which is transmitted to the bit I5. A complete description of an impact drill` embodying certain of these features r isgivenv in myk copending application Serial Number 527 ,f1-7 9, now Patent No. 2,425,012, Where the, operation is also discussed in considerable detail.

In the operation ofthe rotary impact drill shown in Fig. 1, the entire unit is placed in a hole having fluid therein and lowered until the bit I5-encountersthe floor of the hole, whereupon the bit is rotated by revolving the shank4 II. Since the hole is lled with fluid, the space be,- tween the guide tube 35', and the, shank II and body 40 will be filled with fluid, and rotation of the helical blades 30 with the shank I I will urge the fluid upwardly through the housing 35. This fluid will be replaced by other fluid whichY will enter the bottom of the housing 35` as indicated by the arrows, and will eventually pass out; the upper end of the housing, having impinged against the blades 42 of the motor 2'Iv` and the blades 30 of the pump 26 during its travel through the housing. Friction between thefaces of cams 20 and 45.will tend to drive the motor body40 in the same direction as the shank II, but` the pitch of blade 42Yis such that this rotation would tend to force fluid downwardly. However, the fluidcapacity of pump 26 is so much greater than thatof motor 2l' that the pump is the controlling element, and fluid is forced upwardly,l thereby tending to drive the motor in a direction opposite to that of the shank II.

While the friction betweenthe camfaces tends to rotate the body 40` with the shank II, the fluid Within the' well I Il acts upon the blade 42 to provide a frictional drag which opposes this rotation-and as a result the body and the` upper ca m 45 tend to lag behind or be retarded with respectto the lower cam 20. For a more complete description of this operation, reference shouldbe hadto my copending application Serial Number 527,179, now Patent No. 2,425,012. It is-'tou be understood that thefrictional drag is in addition to therpositive drive of motor- 21, and both actto retard the rotation of body 40- with respect to shank II.

It will be realized that the pitch of blades 42 is steep enoughto oiersubstantialresistance -to rotation through the upwardly moving-iluid'but will not begreat enough to seriously retard or cushion the fall of the hammer -after cam 45` has overridden cam 20. If the pitch of the blade 42 isvery. flat, there is a tendency for the hammer to iloatorfall very slowly due to the dashpotlactionV within the housing- 35, thereby reducingthe magnitude of the impactof cam 45 upon cam 20j. However, by proper construction, and the selection .of thek correct pitch for blade 42, substantial resistanceA to rotation may be obtained while permittinga very heavy hammer blow to be` directed against lower cam 20. The same considerations. as to the pitch of the blade extending fromthe motorbody applies to .all of theforms `3Il of the pump 26. This is such an obvious modi- Ilcation that its illustration is not believed necessary in View of the other forms which are shown `in this specification. One of the principal results of such a change would be to increase the weight of the reciprocating members so that a greater impact is delivered to the lower cam 20, should `such a procedure seem desirable. Another modification, that of reversing the pitch of both the blade 3d and the `blade 42 so that the fluid is forced downwardly instead of upwardly, is discussed in conjunction with the modification `shown in Fig. 4.

Description of Fig. 2

In Fig. 2 I have shown a modification wherein a portion of the weight of the guide tube or housing is carried by the reciprocating element. while the remainder of the weight is supported by the non-reciprocating element. In Fig. 2, as in Fig. l, the numeral II indicates `a shank having an operating head I2 at its lower end to which is attached a bit I5, and which is providedwith a lower or shank cam 20. Aiiuid pump 26 is mounted on shank II for rotationtherewith, and between the pump and the lower cam 20 is a fluid motor 21 having an upper cam 45 at its lower end adapted to bear against the lower cam 20. A guide tube or housing 54 encloses the pump 26 and motor 21 as in my previously described form, but the tube is formed in two parts,

,of pump 26. The lower section 56 of guide tube 54 is firmly attached to the helical blades 42 to move with the latter, and all of the reciprocable elements are designed so that they may be raised the full distance of the rise of cams 20 and 45 without hitting the non-reciprocable elements of pump 26.

At the lower end of upper portion 55 of guide tube 54, the housing is enlarged to form a bell 51 which extends downwardly to enclose the upper end of the lower section 56 of the guide tube. The bell 51 is made sufiiciently large so that ample room is provided for the lower section 56 to move within the bell without rubbing or binding, and the lower section may therefore move with the body 40, independently of the upper portion 55 of the guide tube 54. In addition, the provision of the bell 51 insures that all of the uid moved upwardly by pump 26 will be drawn through motor 21 to drive the latter in a manner similar to that described in connection with the form shown in Fig. l.

The advantages of this form of my invention will become apparent when it is realized that an element rotating in a very thick or viscous fluid tends to drive a considerable portion of the fluid with it. The rotation of this fluid, because of friction, tends to rotate the next adjacent sur- 'f-aceor object so that all rotate as a unit. In

the form shown in Fig. 1, guide tube 35 rotates at all times with the shank II and so tends to rotate the fluid within the housing. This movement of the fluid tends to rotate the blade 42 of motor 21, and acts as an additional frictional force tending to cause the rotation of the motor in synchronism with the-shank II. This force is thus in the same direction as that existing be.- tween the faces of the cams 20 and 45 and hence requires the application of a greater contrarotational force to retard the motor 21 with respect to shank II. If the fluid is not too viscous, the energy transferred thereby from the guide tube 35 to the body 40 is not sufficient to cause av substantial change in the retardation of the body with respect to shank II.

However, if the mud or fluid used in the well IU is particularly viscous, the retardation will be decreased and the frequency of impact of the reciprocable elements upon the lower cam 20 will be lmaterially decreased. Consequently, under these conditions I prefer to use the form illustrated in Fig. 2 where the lower section 56 of the guide tube 54 is attached to the blade 42 to rotate in synchronism with the body 40 so that rotational energy of the housing is not transmitted by the fluid to the body. Similarly, the upper portion 55 of the guide tube 54 is connected to the blades 30 so that it rotates in synchronism with shank II,` and there is thus no transfer of rotational energy from the housing to either the pump 26 or motor 21. In addition, the attachment of the lower section 56 of the guide tube 54to the blade 42 increases the weight of the reciprocable members so that the` previously mentioned floating of these members, particularly noticeable in very viscous fluids, is materially decreased.

Description of Fig.` 3

'Io reduce to a minimum any possibility of the reciprocating members floating downwardly to impact against cam 26 when very viscous fluids are used, the form shown in Fig. 3 has been developed in which the vanes or blade-s of the motor have substantially no axial movement but instead merely rotate about the shank II. As in the previously described forms, the shank II is adapted to be attached to the lower end of a drill string and is provided with an operating head I2 at its lower end which is adapted to receive a bit I5 and has a lower or shank cani 20 rigidly attached to its upper surface. In addition, a hydraulic pump 26 is mounted on shank I I and driven by the latter, while a hydraulic motor 6I is mounted on the shank between the pump and the lower cam 2D.

As in the case of the previously described pumps, pump 26 includes a helical blade 3U rigidly attached to shank I I and enclosed within a cylindrical guide tube or housing 60 which is firmly attached to it. Theguide tube 65 and the blade 30 thus rotate with the shank II, and cooperate to move fluid upwardly, thereby providing one of the motive sources for motor 6I. As will become apparent, the motor 6I is somewhat different from the motor 21 used with the previously described form, since it, unlike the others, reciprocates a hammer member while its helical blades have substantially no axial movement. The motor 6I includes a guide tube or housing 62 which is substantially the same diameter as the pump housing 6I) and is aligned with the latter though spaced a slight distance axially therefrom. Centrally mounted withinthe guide 7 tube-i62is a tubular body 63 which is rotatably mounted on shank and which is provided. with alseriesof helical blades 65 attached'to both the body and the housing 62 so that an axial fiow of fluid between the body and the housing will tend to rotate this assembly.

At the lower end of pump 26 I mount a shoulder orcollar 69 on shank li, and provide acooperating shoulder or collar 10 at the upper, end of the tubular body 63 to bear againstand be held by thecollar 69. Upward Vmovement of the body 63 and the'housingY 62 is thus limited, andby the proper positioning of collars 68 and 10, thereis no possibility of guide tube 62 touching guide tube 60.

Slidably mounted within the tubular body 63 at thelower end thereof is a hammer 8| which is rotatably and reciprocably mounted onl shank An upper cam 82, similar to cam 45 and shaped complementally to lower cam' 20, isA firmly mounted on the lower end of hammer 8|. Rotation of upper cam 82 with respect to lower cam will thus raise the hammer 8| and then, as the cams override, permit the hammer to drop and deliver an impact which will be transmitted tobit l5.

To transmit the rotary motion of the hydraulic motor 6| tothe hammer 8|, the latter'is-provided witha series of keyways 00 which extend vertically, parallel to the axis of shank Ii, and are engaged by one or more keys or splines 85 attached to the inner-surface of the lower end of the tubular body portion 63. A suiicient clearance, of course is provided between the hammer 8| and the tubular body-63 to permit the free movement of the hammer with respect to the latter, while the use of keyways 90 and keys 05 insures that the rotary motionof the tubular body 63 will be transmitted to the hammer 8| while the latter moves axially with respect to the body. A

To hold the body 63 in its uppermost position,

I provide a resilient member such as a spring 86 extending between the upper surface of hammer 8| and the lower surface of collar 10. Like the other members of the hydraulic motor assembly 6|, spring 86 is formed toV provide a clearance from shank so that a minimum amount of rotational energy. istransferred from the shank to the tubular body 63. It will be noted that spring 86 carries the weight of the. tubular body 63, the guide tube 62 and the helical'blades, thereby causing acertain compression of the spring which must be taken into consideration when the drill is being designed. In addition, as cams 20 and 82 appproach theirY crests, spring 86 is further compressed until the cams override, whereupon the spring aids gravity in forcing the hammer 8| downwardly to cause cam 82 to impact against cam 20.

The operation of the form shown in Fig. 3 is somewhat similar to that of the previously described forms in that the pump 26 draws fluid upwardly through the guide tubes 60 and 62 to drive the motor 6| which operates the hammer 8|. However, in this form, the spring 86 urges the guide tube 62, tubular body 63, and blade 65 upwardly so that collar 10 bears against collar 69 at all times, and there is thus no reciprocatory motion of these parts of the motor 6|. Their rotary motion, however, is transmittedby keys 95, acting in keyways 90, to the hammer 8|, so that the latter isv reciprocated. as it is rotatedon shank One distinction of this. form from thev previously described forms. is thatl hammer 8| isv separate from motor 6|, whereas in the previously described forms, the hammer. and motor'were combined in a single unit.

As the rotor of motor 6| rotates with respect to shank hammer 8| will likewise be rotated and consequently will be raised by the action of cams 20. and 82. When these cams override, the energy which has been stored in spring 86 during the raisingof the hammer will be returned to drivethe hammer downwardly and produce a greater impact between the-faces of the cams. It. is'possible by a suitable choice of springs 88, rotational speed of shank and other miscellaneous factors, to cause the hammer 8| to oscillate at'a frequency approximately equal to the natural period of oscillation of spring 86. When this occurs, a condition of resonance may be set up which will even further increase the impact delivered to bit I5. It is apparent that various spring suspensions may be used to achieve this result, and for more information in this regard, reference should be had to my copending application Serial Number 674,526 illed June 5, 1946.

Description of Fig. 4

Another modification of my improved impact drillis shown in Fig. 4, and an inspection of the drawing willy show that this form operates in a manner substantially opposite to that of the form shown in Fig. 1. However, certain advantages are secured by this reverse operation which are not obtainable by using the form shown Yin Fig. 1, and .these advantages will sometimes indicate the use of this form in preference to those previously described.

As in my previously described forms, a central shank |00 is provided with an attaching or coupling means |0| at its upper end, adapted to be connected to the lower end of a drill string |02 of the usual type. An operating head |03 is connected to the lower end of shank |00 and is adapted to receive a bit |05 of the type customarily used in earth boring.

Near the upper end of shank |00 I provide a hydraulic pump |06 which includes one or more helical blades |01 welded or otherwise securely attached tothe shank |00 and enclosed within a guide tube or housingV |08 which is preferably Welded to the blades. At its upper end, the guide tube |08 extends for a substantial distance above the helical blades |01 and is necked in to form a constricted portion |00 which abuts shank |00 at its extreme upper end. In this Constricted region .|09 I provide a series of slots or apertures I5 which p-ermit the passage of uid into guide tube |08 while preventing the admission of larger stones and other detritus therein. In addition, attaching the upper end ofthe constricted portion |09 to the shank |00 provides a stronger and more rigid construction for this equipment which is normally subjected to very rough usage.

Below pump |06 and above operating head |03 is a hydraulic motor |20 which is similar to the motor 21 previously described in connection with the forms shown in Figs. 1 and 2. As indicated in Fig. 4, motor |20 includes -a central body |25 rotatably and reciprocably mounted on shank |00 with one or more helical blades |26 firmly attached thereto. Guide tube or housing |08 extends downwardly below the lower end of blades |01 of pump |06 to enclose the blades |26 of motor |20, and the blades of the latter are provided with a pitch `opposite to that of blades |01 so that rotation of the pump in one direction will tend `to drive the motor in the opposite direc- 9 l, tion. Blades |26, are, of course, provided with sufficient clearance from guide tube |08 so that they may rotate freely with respect to the latter.

The lower end of the central body |25 is provided with an upper cam |21 which is adapted to cooperate with -a lower cam |28 mounted on the operating head |23' to raise and drop the reciprocable members including the body |25, blades |26 and cam |21.l It should be noted that in this construction, as in the forms shown in Figs. 1 and 2, the motor and hammer are integral and the whole motor reciprocates upon shank when it is rotated with respect thereto.

To complete the drill, the lower end of guide tube |08 is extended downwardly to a point adjacent the operating head |03 where it is provided with a collar |2| which may be held to the operating head, and which is provided with a series of orices |22 adapted to direct the fluid downwardly onto bit |65. With this construction, guide tube |08 is firmly mounted on shank |00 at both the upper and lower ends of the former and a very rugged device is provided.

In the operation of the device, fluid is forced through the drill string |02 and out through an orifice in the bit from whence it then moves upwardly carrying bits of rock and other detritus with it. When the drill string |02 is being rotated in the direction indicated by the arrow, a portion `of this fluid will be drawn inwardly through the apertures ||5 of the constricted p0rtion |09 where it will be forced downwardly by the action of pump |06. The fluid then impinges against the blades |26 of motor |20 to urgethe blades and body |25 in a direction opposite to that of the shank |00, thereby causing cam |21 to rotate and override the lower cam |28. As a result, the body |25 is raised and then dropped to deliver an impact which is transmitted to bit |05, while the fluid which has completed its passage through housing |08 is directed downwardly by orifices |22 against the bit where a washing action of the latter takes place. This fluid again moves upwardly, on the outside of the guide tube |08, land a portion of it is again drawn in through apertures |I5 while the remainder moves upwardly through the well as is customary in such work.

It will thus be seen that the modification shown in Fig. 4 is similar to that shown in Fig. 1 with the exception that the hydraulic motor is located so as to be on the outlet or pressure side of hydraulic pump |06 and the passage of the hydraulic fluid or mud is axially downward through housing |08. Furthermore, this down# ward movement of the fluid acts to wash the bit |05, and involves a recycling of a portion of the lluid through the housing instead'of requiring but a vsingle passage therethrough.

l Description of Fig. 5

in Fig. 5 1 have shown a modification which combines the forms-shown in Figs. 1 and 4 to provide a drill having a, centrally mountedy fluid motor with a hydraulic pump on either side thereof. The use of such a form will be particu-4 larly advantageous where a very viscous fluid or' mud is being used, and it is important that the greatest possible amount of energy be delivered to the motor section of the device. In addition,` this combination assures a more steady flow of fluid through the motor and minimizes pocketing or builing action of fluid passing through the pump and impinging upon fluid traveling Iin an opposite direction from the motor. In this lOl form,a shank |30 is adapted to be attached at its upper end to a standard drill stem and has an operating head 3| at its lower end. On the upper" surface of operating head |3| I mount a shankr 0r lower cam |132, and provision is made for -the attachment'of a bit |33 to the lower end of the head.

Near the upper end of shank |30 I mount a hydraulic pump |35, and near the lower end I mount a second pump |36. Between the .pump's' |35 and |36 I mount a hydraulic motor |31 which is driven by the stream of fluid moved by' the pumps. Pump |35 includes one or more helical blades |40 which are welded or otherwise securely attached to shank |30 for rotation there' with, and includes a guide tube |4| which encloses pump |35, motor |31, and pump |36. If desired, the guide tube |4| may be provided with apertures at its upper end similar to the apertures ||5 of the form shown in Fig. 4, and

it is preferably provided with orifices |43 at its lower end which will direct a stream of fluid against the bit |33. Guide tube |4| is firmly attached to helical blades |40 of pump |35, and vat its lower end is provided with interiorly extendinghelical blades |45 which cooperate with the other elements to form pump |36. Helical blades |40 and |45 thus rotate with the shank |30 at all times, and their pitches are'so correlated that both tend to move the same quantity of fluid through tube |4| for each revolution of the shank.

Motor |31, which is reciprocably and rotatably mounted on shank |30 between pumps |35 and. |36, includes a central tubular body portion '|46' having one or more helical blades |41" rigidly attached thereto. These blades |41 have a' pitch opposite to that of helical blades |40 and |45 of pumps |35 and |36, respectively, and are formed to have a sumcient clearance between them and the guide tube |4| to permit their free rotation with respect to the tube. Similarly, blades |45 of pump |36 are'spaced from the central tubular body |46 so that no rubbing be" tween the two occurs. The lower end of body |46 is provided with a hammer or upper cam |50 which is shaped complementally to cam |32 so that relative rotation of the two cams will cause them to override each other, lifting body |46 and:

then permitting it to drop to deliver an impact` which is transmitted to the bit |33.

The operation of this form of my device is quite similar to that of the previously described forms shown in Figs. 1 and 4. Whenfluid which has been forced down the drill string emerges from the usual outlet in bit |33, this fluid movesv upwardly between the walls of the hole and the outside of guide tube |4| until the top -of the" latter is reached. At this time, .a portion of this fluid is drawn into the guide tube and forced;

downwardly by the action of blades |40 of pump |35, and the fluid then strikes blades |41 ofV motor |31. Because of the pitch ofthe motorblades, the fluid urges them to rotate ina direction opposite to. that of shank |30 so that arotational; differential willbe setup between` body |46 and shank |30. Thel fluid then passes from motor |31 to pump |36 where blades |45, in effect,V suck the fluid downwardly through motor |31 to assist in driving the latter. Fluid from pump |36 is discharged through orifices |43 to impinge against bit |33 and assist in wash` ing the latter. The fluid then passes upwardly between the walls of the hole and the outside of housing |4|,` and a portion of this fluid is area51, ssa

then recycled by passing it4 again through pumps' [35, and [3.6, and motor |3;'l.y As body M Bis. ro.- tated cam.. [50. is. rotated. with respect. tocam: |:32.,. so that the two override each other and. theibody'isrst lifted and then dropped, as previously described, s that when the. various fric.- tional forces tending to rotate body 145 with shank 1.3.0 are; overcome, thev body is reciprocated to provide impacts which vare transmitted. toY bit |33.;

In the variousvv modiicationsr of this. invention. which I. have illustrated, the drills may be roughly divided into two portions of which. the first or driving portion includes the shank,V thepump, the driving cam, and the` bit. The secondor driven portion includes the motor, the hammer, and the driven cam; and the retardation ofthe driven portionwith respect to the driving; portion operates the impact meansin the: drill.. In each of the forms shown, the driving portion is rotated by its connection to the drill: stem= and the. driven portion is urged' to rotate wi-thl the driving portion by frictional forces, suchl as. that existing between the shank a-nd. hammer cams, until the force exerted bythe motor meansis suflicient to overcome the' frictional force.` When. this occurs, the` motor portion' rotates with respect to the drivingportionf, and the hammer portion is reciprocatedas. described.

The motor portion of the drill may belocated either in the inlet or suction side' of. the 'pumps or in the outlet or pressure side thereof; I have shown examples. of both. forms, of which. the modicationsin Figs; 11.7,. 2 and 3Y show the: motorl in .theinlet` or` suction side,A and the form shown in Fig. 4' showsthe motor in the outlet ory pres-Y sure side. In Fig. 5,- these two types. have been`4 combined to provide: a motor between two pumps-` so\ that the. former isv in thev pressure orl outlet, side of one pump and inthe'inlet or suction side of the.l other pump. It would. be possible,l of course, tov make a dri-ll having two motors with a pump between them,v shouldv this be. desired.. In additiomit. will be apparent that other medincations may be .madein these devices, such as the use.- of an independentv hammer' and` motor combination `such as shownv in- Figi. 3. Various other combinations; and modifications mayA be: made which are so numerous as.v to make. de= scription and illustration ofv them. impractical.

The hydraulic pump and. motor combination described herein is adapted for use in a wide varietyl of impact means, some ofV whichl are shown in one or more or"A my copending applica.- tions. ./isv previously mentioned, these applica.n tions show the. usey of a hammer whiclris retarded' with respect'. to a rotated drill. stem so: that cams between the hammer and the drill override and thereby reciprocate the hammer to deliverA impacts to abit on the: drill. vIn my' prior drills. as shown in my previously' mentioned'A copending. applications', I have used a rotation retarding means which relies solely on the trictional eects securedy by the rotation offblad'es in a fluid.A Certain. other drills have used hydraulic power secured from the luidl circulatory systelfn.1 to. operate an impact' means. Differing from these prior forms, `the drill of my present. invention provides a seit-contained unitoperated solely by the rotational energy derived from the drill stem to operate a. hydraulic pump and motor conrbination located in. the well hole above the bit to actuate the hammer of the drill.

While I have shownV and described different forms of my invention., ity will be apparent that modicationsf, suchv as: those previously sug-v on said shank and attached thereto in such amanner that rotation` of saidf shank drives. iiuidv axially along the outside of. said shank;. rotor means mounted on the outside of said. shank and rotatable with respectthereto, said rotor means including a tubular body memberV reciprocably mounted on said shank, and said rotor means being urged to rotate with respect tosaid shank by i'mpingement thereon of the fluid moved by said driving means ;i and housing mea-ns enclosing said driving and rotor means to guide said. iuidl therethrough; and cam means connectedbetween said rotor and said shank for axial reciprocation along said shank when relative rotation. occurs between said. rotor and. said shank, said cam means including a cam surface attached tov the lower portion or said shank for rotation therewith, anda complemental cam surface attached to the immediately adjacent por* tion or the tubular body member of said rotor means.

2; An impact drill which includes: a shank adapted to' be rotated; helical blade means. mountedl on said shank and' attached thereto in such a manner that rotation of said. shank is adapted; to cause fluid to move axiallyy along the outside of said shank; a. fluid rotor mounted; on said. shank for rotation with respect thereto, and including a body portion and a blade attached thereto in such a manner that said fluid moved byy said pumpwill impinge against said blade to ur'geit and said bodyto rotate with respect to,- said shank; housing meansv enclosing both of. said blade means' to guide said fluid therethrough and cam. means` connected between said rotor and said shank for. axial reciprocation along said shank when relative rotation occurs between. said rotor and saidI shank.

3. An impact drill which includes: a rotatable shank adapted to receive a bit at its lower end; lluid pumpmeans mounted on the exterior of said shank and. driven by the rotation of said. shank to move a fluid axially along the outside of said shank; fluid motor means mounted on the exterior of said shank for rotation with respect thereto and adapted to be driven by said uid. moved by said pump; and, cam means connected between. said motor and said shank for axial reciprocation along. said shank when rel.- ative rotation occurs between said motor and said shank, said cam means thereby causing impacts that are delivered to the bit-receiving end of said shank.

4. An impact drill which includes: a rotatable shankY adapted to receive a bit at its lowerend;- pump blade meansA mounted onthe exterior ci said shank'. and driven by the rotation of said. shanky to move a fluid axially along the outside of said shank; motor blade means mounted. on the exterior of said shank driven by said fluid axially moved by said pump and rotated thereby in a direction opposite to that of saidV shank; housing means enclosing said pump and motor to guide said fluid through said pump andmotor; and camv means connected between said' motor and said shank foraxial reciprocation along said shank when relative rotation occurs between said motor and said shank, said cam meansthereby causing impacts that are delivered to the bitreceiving end of said shank.

5. An impact drill which includes: a rotatable shank adapted to receive a bit at its lower end; a fluid pump mounted on the exterior of said shank and driven by the rotation of said shank to move a iiuid axially along the outside of said shank; a fluid motor mounted on the exterior of said shank for co-axial rotation with respect thereto in a direction opposite to that of said shank and driven by said axially driven nuid moved by said pump; housing means enclosing said pump and motor to guide said fluid moved by said pump through said motor; and cooperating cam means connected to said shank and said motor for operation by the relative rotation of said shank and motor, said cam means thereby causing impacts which are delivered to the bit-receiving end of said shank.

6. An impact drill which includes: a rotatable shank adapted to receive a bit at its lower end; a helical blade attached to said shank for rotation therewith; a housing attached to said helical blade for rotation therewith, and extending below the lower end thereof, said blade having a pitch such that normal rotation of said shank is adapted to urge uid upwardly through said housing; a tubular body rotatably and reciprocably mounted on said shank below said blade and extending upwardly within said housing; a helical blade attached to and mounted on the exterior of said body for rotation therewith, the pitch of said last mentioned blade being opposite to the pitch of said rst-mentioned blade; and cam means attached to and between said body and said shank, adapted to raise said body and then drop it as said body rotates relative to said shank, whereby an impact is delivered to the bitreceiving end of said shank.

7. An impact drill which includes: a rotatable shank adapted to receive a bit at its lower end;Y a helical blade attached to the outside of said shank for rotation therewith; a housing attached to said helical blade for rotation therewith, said blade having a pitch such that normal rotation of said shank is adapted to urge fluid upwardly through said housing; a tubular body rotatably and reciprocably mounted on said shank below said blade and housing; a helical blade attached to said body for movement therewith, said last mentioned blade having a pitch such that upward movement of fluid along said blade tends to rotate said body in a direction opposite to that of said shank; a second housing attached to said last mentioned blade for movement therewith, and adapted to direct the fluid moved upwardly by said first mentioned blade, along said last mentioned blade, whereby rotation of said shank in one direction tends to establish a rotation of said body in a direction opposite to that of said shank; and cam means attached to said tubular body and said shank, adapted to raise said body and then drop it as said body rotates, whereby an impact is delivered to the bit receiving end of i said shank.

8. An impact drill which includes: a rotatable shank adapted to receive a bit at its lower end; a helical blade attached to the outside of said shank for rotation therewith; a housing attached to said helical blade for rotation therewith, said blade having a pitch such that normal rotation of said shank is adapted to urge fluid upwardly through said housing; a tubular body rotatably mounted on said shank below said blade and housing; a helical blade attached t-o said body for movement therewith, said: last mentioned blade having a pitch such that upwardly movement of uid along said blade tends to rotate said body in a direction opposite to that of said shank; a second housing attached to said last mentioned blade for movement therewith, adapted to direct the fluid moved upwardly by said rst mentioned blade, along said last mentioned blade, whereby rotation of said shank in one direction tends to establish a rotation of said body in a direction opposite to that of said shank; a hammer body rotatably and reciprocably mounted on said shank within said tubular body, and reciprocable with respect to the latter; spring means extending between said hammer body and said tubular body to urge the latter upwardly at all times; and cam means attached to said hammer body and said shank adapted to raise said body and then drop it as said body rotates with respect to said shank, whereby an impact is delivered to the bit receiving end of said shank.

9. An impact drill which includes: a rotatable shank adapted to receive a bit at its lower end; a helical blade attached to the outside of said shank for rotation therewith; a housing attached to said helical blade for rotation therewith and extending below the lower end thereof, said blade having a pitch such that normal rotation of said shank is adapted to urge iluid downwardly through said housing; a tubular hammer body rotatably and reciprocably mounted on said shank within said housing below said blade; a helical blade attached to said hammer body for movement therewith, the pitch of said last mentioned blade being such that downwardly moving uid will tend to rotate said body in a direction opposite to that of said shank; and cam means attached Vto said hammer body and said shank adapted to raise said hammer body and then drop it as said hammer body rotates with respect to said shank, whereby an impact is delivered to the bit-receiving end of said shank.

10. An impact drill which includes: a rotatable shank adapted to receive a bit at its lower end; a helical blade attached to the outside of said shank for rotation therewith; a housing attached to said helical blade for rotation therewith, and extending below the lower end thereof, said blade having a pitch such that normal rotation of said shank is adapted to urge fluid downwardly through said housing; a tubular` body rotatably and reciprocably mounted on said shank within said housing below said blade; a helical blade attached to said body for movement therewith, the pitch of said last mentioned blade being such that downwardly moving fluid will tend to rotate said body in a direction opposite to that of said shank; a helical blade attached to the interior of said housing below said second mentioned helical blade for rotation with said shank and with respect to said body, the pitch of said last mentioned helical blade being such that it tends to move iluid downwardly through said housing; and cam means attached to said body and said shank adapted to raise said body and then drop it as said body rotates with respect to said shank, whereby an impact is delivered to the bit-.receiving end of said shank.

11. An impact drill which includes: a rotatable shank adapted to receive a bit at its lower end; a helical blade attached to the outside of said shank for rotation therewith; a housing substantially co-axal with said shank, attached to said helical blade. for. rotation therewith, andextending below the. lower end thereof, saidblade having a pitch such that normal rotation'` of; said shank isr adapted to urge.r fluid upwardly through said housing.; a tubular body rotatably' and reciprocably mounted on saidl shank, Within said housing below said blade; ahelical blade attachedto and mounted on the exterior of said body for rotation therewith, the pitch of said last mentionedblade being opposite to the pitch oi said first-mentioned blade; a cam member: attached tothe lower endv ofsaid shankfor rotation therewith; and a complementallyshaped cam attached to the lower end of said body, adapted to raise saidv body and then drop it'. as said cams rotate with respect to each other by reason of the rotation of` said body with respect to said shanks, whereby an impact is delivered to said shank cam which is transmitted to the bit-receiving end of said shank.

12. An impact drill. which includes: a rotatable shank adapted to receive a bit at its lower end; a helical blade attached to the outside of said shank for rotation therewith; a housingV substantially co-axial with said shank, attachedv to said helical blade for rotation therewith, and havingv a bell portion at its lower end, said blade having a pitch such that normal rotation of said` shank is adapted' to urge fluid upwardly` through said housing; a tubular body rotatably and reciprocably mounted on said shank below said` blade and housing; a helical blade attached to said body for movement therewith, said last-mentioned blade having a pitch such that upward movement of fluid along said blade` tendsv to rotate said body in a direction opposite to that of saidI shank; a second housing substantially coaxial with said shank and slidably tting into said belli portion of said rst mentioned housing,

said housing being attached to said last men= tioned blade for movement therewith, and adapted d direct the fluid' moved upwardly by said first mentioned blade, along said last mentioned blade, whereby rotation of said shank in one direction tends to establish a rotation of said body in a direction opposite to that of said shank; a cam member attached to the lower end of said shank for rotation therewith; and a complementally shaped cam attached to the lower endof said tubular body, adapted to raise said body and then drop it as said cams rotate with respect to each other by reason of the rotation of said body with respect to said shank, whereby an impact is delivered to said shank cam which is transmitted to the bit-receiving end of said shank.

13. An impact drill which includes: a rotatable shank adapted to receive a bit at its lower end; a helical blade attached to the outside of said shank for rotation therewith; a housing substantially coaXial` with said shank, attached to said` helical blade for rotation therewith, said blade having a pitch such that normal rotation of said' shank is adapted to urge fluid upwardly throughy said housing; a shoulder formed on said' shank at the lower end of said blade and housing; a tubular body rotatablymounted on said shank below said blade and housing; a helical blade attached to said body for movement therewith, said last mentioned blade having a pitch such that upward movement of fluid along said blade tends to rotate said body in a direction opposite to that of said' shank; a second housing substantially coaxial with said shank attached to said last men--4 tioned blade for movement therewith, adapted to 16' direct the fluid moved upwardly by said iirst mentionedl blade, along said last mentioned blade, whereby rotation of said shank in one direction tends to establish a rotation of said body in a direction opposite to that of said shank; a hammer body rotatably and reciprocably mounted on said shank within said tubular body, and reciprocable with respect to the latter, said hammer body and said tubular body being connected by splines and keyways to prevent the transmission of reciprocable motion therebetween whiletransmitting rotary motion; spring means eX- tending between said hammer body and said tubular body to urge the latter upwardly against said shoulder at al1 times; a cam member attached to the lower end of said shank for rotation therewith; and a complementally shaped cam attached to the lower end of said hammer body, adapted to raise said body and then drop it. as said cams rotate with respect to each other by reason of the rotation of said body with ree spect to said shank, whereby an impact is delivered to said shank cam which is transmitted to the bit-receiving end of said shank.

14,. An impact drill which includes: a rotatable shank adapted to receive `a bit at its lower end; a helical blade attached to the outside of said shank for rotation therewith; a housing substantial'ly co-aXial with said shank, attached to said helical blade for rotation therewith, and eX- tend'ing below the lower end thereof, said blade having a pitch such that normal rotation of said shank isY adapted to urge fiuid downwardly through said housing; a strainer portion formed at the upper end of said housing to prevent' the admission therein of large members; a tubular body rotatably and reciprocably mounted on said shank within said housing below said blade; a helical blade attached to said body for movement therewith, the pitch of said last mentioned blade being such that downwardly moving uid will tendy tol rotate saidV body in a direction opposite to that. of said shank; jet means at the lower end of said housing to discharge said iiuid, after its passage therethrough, against said bit; a cam member attached to the lower end of said shank for rotation therewith; land a complementally shaped cam attached to the lower end of said body adapted to raise said body and then drop it as: saidv cams rotate with respect to each other by reason of the rotation of said body with respect to said shank, whereby an impact is delivered to said shank cam which is transmitted to the bit-receiving end of said shank.

15. An impact drill which includes: a rotatable shank .adapted to receive a bit at its lower end; a helicalv blade attached to the outside of said shank for rotation therewith; a housing substantially co-axial with said shank, attached to said helical blade for rotation therewithy and extending below the lower end thereof, said blade having a pitch such that normal rotation of said shank is adapted to urge fluid downwardly through said housing; a strainer portion formed at the upper end of said housing to prevent the admission therein of large members; a tubular body rotatably and reciprocably mounted on said shank within said housing below said blade; a helical blade attached to said body for movement therewith, the pitch of said last mentioned blade being such that downwardly moving uid will tend to rotate said body in a direction opposite to that of said shank; a helical blade attached to the interior of said housing below said second mentioned helical blade, spaced from said tubular body for rotation with respect thereto, the pitch of said last mentioned helical blade being such that it tends to move fluid downwardly through said housing at the same rate as that of said first mentioned helical blade; jet means at the lower end of said housing to discharge said uid, after its passage therethrough, against said bit; a cam member attached to the lower end of said shank for rotation therewith; and a complementally shaped cam attached to the lower end of said body adapted to raise said body and then drop it as said cams rotate with respect to each other by reason of the rotation of said body with respect to said shank, thereby an impact is delivered to said shank cam which is transmitted to the bit-receiving end of said shank.

16. An impact drill which includes: a rotatable shank adapted to receive a bit at its lowest end; a fluid pump mounted on the exterior of said shank adjacent its lower end for movement therewith, `and including a helical blade; a generally tubular member rotatably and reciprocably mounted on said shank for movement with respect thereto; a second helical blade of opposite pitch attached to the exterior of said tubular member for movement therewith, axially aligned with said pump in a manner to be rotated with respect to said shank by uid moved axially along said shank by said pump; a cylindrical member enclosing said helical blades to direct fluid therebetween; and cam means connected between said tubular member and said shank for axial. reciprocation along said shank when relative rotation occurs between said tubular member and said shank, said cam means thereby causing impacts that are delivered to the bit-receiving end of said shank.

ROBERT E. SNYDER.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 460,369 Canan Sept. 29, 1891 466,660 Duncan Jan. 5, 1892 1,348,815 Lewis Aug. 3, 1920 1,462,975 Mathews July 24, 1923 1,526,748 Herman Feb- 17, 1925. 1,607,082 Howcott Nov. 16, 1926 2,246,418 Froome et al June 17, 1941 2,287,157 Woli June 23, 1942' 2,352,412 Sandstone June 27, 1944 2,376,974 Miller May 29, 1945 2,425,012 Snyder Aug. 5, 1947 

